This comes to us from BimmerBoost sponsor Burger Tuning (BMS) who decided to put together a few dyno charts showing the difference between the stock N54 twin turbochargers maxed out, upgraded twin turbos, and the single turbo conversion. These all come from a E9X 335i with an automatic transmisison. As one would expect, the single turbo shifts the powerband to the right making for more peak horsepower but less torque through the entire curve and down low compared to the upgraded twins.

More insight from Terry@BMS:

A couple interesting charts to check out.

The first is maxed out OEM turbos compared with RBs. Both done on the same car a few months apart.

The second is RBs compared with a single turbo running higher octane and meth. It's an interesting comparison with the single as both cars are automatic so you get an apples to apples feeling for the power curves.

The single turbo clearly has the edge from 5700-6500rpm but for all around street car use does that gain make up what is lost below 4000rpm? In terms of racing I'd love to see what the 335 auto single runs 60-130. Is it going to be in the 6s or are we looking more like low 7s? Our 135 is around 140# lighter, but makes maybe an average of 35whp less from 5700rpm+ to redline, so I'm curious just how far behind it would wind up. Hopefully I can get some 60-130 testing on ours done this weekend.

My commute is the same with half highway and the other half stop & go.. I sold my manual Supercharged E92 M3 coupe to get my E92 335xi coupe auto with paddle shifters simply because of the PITA it was with the manual.. I never thought I would enjoy an Auto but after driving a few DCT M3's both NA and boosted I was sold. Understand I do not have the DCT in my XI although I wish BMW would add the option to the XI model, I do like my FBO 335xi with m-sport package as a daily driver and I can smoke my M3 in the 1/8mile and slap on some snows for the winter Best of both worlds IMHO

Wow... Never saw someone switch from a M3 to a 335. Usually, its the other way around. Why not opt for the M3 DCT? Or did you drive the xi and immediately fell in love?

I saw that... I love how the "ultimate driving machine" is slowly becoming less and less a drivers car

When it comes time to get a different car I'll probably pick up a C5 Z06

I was offered a really good deal on a TT Z06 this summer. I went and test drove it and really didn't like it. oh well. I plan to keep this car for a while but I'm real interested in the M2. I LOVE the 1M and hope the M2 is just as fantastic a car for a lot smaller price

I was offered a really good deal on a TT Z06 this summer. I went and test drove it and really didn't like it. oh well. I plan to keep this car for a while but I'm real interested in the M2. I LOVE the 1M and hope the M2 is just as fantastic a car for a lot smaller price

Same here, I'm in no hurrry to dump the N54 so I'm just going to wait and see what happens.

I'll bite as well. This is an honest question, and I hope it gets treated as such. A lot of people keep making similar comments about how they'd rather have power at 3000 rpm or have 400 ft-lbs at 2500 rpm. My COBB tune fell under this category, so I do know what it feels like, it isn't a problem of not understanding what low-end torque feels like. I'm just curious, what is the appeal of having power down low and then tapering off at 5000-5500? If you watch Terry's own RB test video, he launches at 2k, quickly hits 5k, shifts at about 6800, and upon shifting it only drops down to about 5400, and then 5600 on the next shift. So unless I'm missing something, a lot of the time was spent above 5500 rpm.

I'm just trying to figure out why people hate on the single turbo when it makes power, and continues to climb, in the range that you actually stay in when going wide open. Obviously if you don't ever take your car beyond 4k, it makes sense, but if you're driving like that, I'm not sure why you'd care about power anyways. Are you guys really just getting on it from 2000-4500 rpm and that's it?

For full disclosure, I do have a single turbo, however I have not pushed it yet as it's not finalized. I hope this does not come off as a biased post, hence the honesty about my setup. I'm not trying to say "565rwhp, end of story, the rest doesn't matter", but considering everyone keeps praising the 60-130 times, something doesn't add up to me.

I'll bite as well. This is an honest question, and I hope it gets treated as such. A lot of people keep making similar comments about how they'd rather have power at 3000 rpm or have 400 ft-lbs at 2500 rpm. My COBB tune fell under this category, so I do know what it feels like, it isn't a problem of not understanding what low-end torque feels like. I'm just curious, what is the appeal of having power down low and then tapering off at 5000-5500? If you watch Terry's own RB test video, he launches at 2k, quickly hits 5k, shifts at about 6800, and upon shifting it only drops down to about 5400, and then 5600 on the next shift. So unless I'm missing something, a lot of the time was spent above 5500 rpm.

I'm just trying to figure out why people hate on the single turbo when it makes power, and continues to climb, in the range that you actually stay in when going wide open. Obviously if you don't ever take your car beyond 4k, it makes sense, but if you're driving like that, I'm not sure why you'd care about power anyways. Are you guys really just getting on it from 2000-4500 rpm and that's it?

For full disclosure, I do have a single turbo, however I have not pushed it yet as it's not finalized. I hope this does not come off as a biased post, hence the honesty about my setup. I'm not trying to say "565rwhp, end of story, the rest doesn't matter", but considering everyone keeps praising the 60-130 times, something doesn't add up to me.

Transient response, drivability, and having the most power for the smallest peak power.

I'll bite as well. This is an honest question, and I hope it gets treated as such. A lot of people keep making similar comments about how they'd rather have power at 3000 rpm or have 400 ft-lbs at 2500 rpm. My COBB tune fell under this category, so I do know what it feels like, it isn't a problem of not understanding what low-end torque feels like. I'm just curious, what is the appeal of having power down low and then tapering off at 5000-5500? If you watch Terry's own RB test video, he launches at 2k, quickly hits 5k, shifts at about 6800, and upon shifting it only drops down to about 5400, and then 5600 on the next shift. So unless I'm missing something, a lot of the time was spent above 5500 rpm.

I'm just trying to figure out why people hate on the single turbo when it makes power, and continues to climb, in the range that you actually stay in when going wide open. Obviously if you don't ever take your car beyond 4k, it makes sense, but if you're driving like that, I'm not sure why you'd care about power anyways. Are you guys really just getting on it from 2000-4500 rpm and that's it?

For full disclosure, I do have a single turbo, however I have not pushed it yet as it's not finalized. I hope this does not come off as a biased post, hence the honesty about my setup. I'm not trying to say "565rwhp, end of story, the rest doesn't matter", but considering everyone keeps praising the 60-130 times, something doesn't add up to me.

i dont have a single turbo, what i do have is a car that is very peaky in hp/rpm. i can tell you, comparitively, it sucks. i rode in a stock turbo fbo car and the thrust in which it put me in my seat, it with 380ish HP compared to my 500ish, was night and day..

That's mostly TQ, that's what puts you back in the seat, and why I still feel like the SC M3s are slow, even though they aren't...when I say they feel slow, I mean that literally...they feel that way.

For everyone else in this discussion...the single turbo cars are making about the same peak TQ that RB turbo cars are making, which is by design, per Shiv's admission of such. The RB turbo cars cross the 400wtq mark about 1,000 rpm earlier than the ST cars, though IDK about the rest of you, I'm never loading up my engine under 3k on the street, as I prefer my crankshaft to rotate intact. And fair enough, they do cross the line earlier than the RB cars. We should also remember that up until this time, the TQ of the ST cars have been severely limited thus far in order to prevent FIERY DEATH from a rear end, cast piston or rod that might break and cast a bad tone over Shiv almighty's ST setup, so under normal conditions, the ST car's midrange TQ would positively FLY past the RB numbers. Meanwhile, the RB turbo cars TQ starts to fall off around 5300 RPM, having gone under 450wtq around the 5900 mark, while the single turbo makes torque right up until the pre-shift timing pull of the AT begins. Now I don't have one of those stupid pansy boy AT transmissions (come at me bro), so I'm able to actually use my powerband up high. That being the case, with an ST, I'd have a flat TQ curve basically until redline (with the way that Shiv tuned his; personally, I'd want to see how much midrange insanity the car could dish out without limitation). Which would mean that I would spend well over 1,000 RPM making significantly more WTQ (minimum 100wtq) than the RB car, not to mention HP. And let's not forget about all the midrange TQ/HP that Shiv left on the table to prevent bad PR. Listen, I'm taking no stance on Shiv, because frankly, this analysis has nothing to do with him, it has to do with a single on the n54. And as far as a single on the n54, I think it's hard to argue how much better it is for power in both the midrange and top end, because many of you guys ironically have amensia regarding the fact that Shiv is limiting the midrange to prevent a PR snafu, something I would expect everyone to jump all over. Rob Beck makes a great product, don't get me wrong, and for a daily driver, I think it's a great, cost effective option for many. But seriously, comparing an independently done ST setup and an RB setup, and claiming that the RB setup will be faster, is simply dumbass nuthuggery. While it probably wouldn't be an FFTEC setup, I know which one I'd put in my car.

I think this whole manual vs DCT vs SMG vs Automatic thing is a bit ridiculous. The latest M5 is only available with a manual transmission only in the US market. I think there is a stigma in America where you are a better driver/bigger man/etc. if you drive a manual. In other countries - the reason people used to drive manual boxes was due to the increased fuel efficiency that came along with it. Here - it's always been about maximum performance. DCT transmissions are superior to a manual - there is no doubt about this. If your reason for driving a manual was for performance reasons - it's no longer a valid argument. While every other - more driver involved countries/countries that engineer these cars moves to a better technology, we are forcing manufacturers to offer us a manual option so we can feel better when talking about our car. It's sad - like the honey boo boo analogy, I think it's because we care too much about what others think than any other real world reason. I saw a brand new M5 in my parking garage - parked next to my M3. I peered inside the window and saw the manual transmission. I thought to myself "why?" - he literally is losing almost a half second in the quarter mile - for no cost, he could have had a much faster car. Taken to a real racetrack - the manual will lose again given good drivers in both.

I understand the driver involvement part (slightly) - but if you keep a DCT in non-automatic mode, the only difference is you aren't controlling clutch engagement. Although you can "dump the clutch" or "modulate" the clutch via commands (LC or "burnout mode") - its not a completely manual process - I understand that. I just don't understand not accepting a better technology just because you have to explain "it's not an automatic or a manual" when someone asks if your car is "a stick". That to me is the issue - every other country who had a high percentage that drove a manual transmission are moving to this technology. Not because of any other reason but understanding its better for performance and efficiency. Heck, even the next generation Corvette is supposedly going to be getting a DCT - this by no argument cannot be called anything other than a proper sports car. I don't understand the fuss about this. F1 cars use sequential gearboxes, NASCAR rows their own. Would you rather have a NASCAR, or even take the sport seriously just because they drive manuals?